Tumbaga is a special type of metal made by mixing two other metals together, usually gold and copper. Imagine you have two cups of different colored candies, one gold and one copper. If you mix these two cups of candies together, you get a new cup of candy that has both colors mixed up! Tumbaga is like this candy mixture, but instead of colors, it's two metals that create a new one.
Tumbaga was used a lot by ancient people like the Aztecs and Incas to make jewelry and other decorations. They used it because it was easy to work with, meaning they could shape it into different designs, and it was also very pretty to look at, shining brightly like gold but not as expensive.
Nowadays, tumbaga is not used as much as it used to be, but some people still appreciate its unique properties and use it for jewelry-making and other crafts. So, if you have a necklace or a bracelet made of tumbaga, it means that it's a special kind of metal that's made by mixing two others together!